Magnetized grounding electrode



P 1951 w. B. HARPMAN 2,568,068

MAGNETIZED GROUNDING ELECTRODE Filed Dec. 25, 1949 ILIIIIIIiII/II 111/111 1/ 1| INVENTOR.

Eatented Sept. 18, 1951 UNITED STATES PATENT OFFICE 6 Claims.

This invention relates to grounding electrodes and more particularly to grounding electrodes having permanent magnets incorporated therein for creating magnetic fields in the area of the grounding electrode.

The principal object of the invention is the provision of a grounding electrode adapted for use in grounding static electric currents generated in dry cleaning washers, dryer and the like.

A further object of the invention is the provision of a grounding electrode having a magnetic field and adapted for use in grounding static electric currents when placed in proximity to elements generating such currents.

A still further object of the invention is the provision of a grounding electrode of a simple, inexpensive construction for efliciently grounding static electricity in various moving objects.

It is known in the art that many and various attempts have heretofore been made to effectively ground static currents arising as a result of or in conjunction with various industrial processes and including the formation or processin of sheet materials, the treatment of various materials in rotating or agitating vessels and in the cleaning or treating of garments in solvents of a dielectric nature.

t is also known that the mean for establishing ground paths for static electric currents as generated by such apparatus has heretofore been relatively expensive in initial construction, installation and maintenance and sometimes incapable of achieving their desired result.

The present invention relates to a simple and inexpensive grounding electrode incorporating a permanent magnet establishing a magnetic field around and about the electrode enabling the same to efficiently provide a ground path for static electric current whereby the same will be efiiciently drained from the device, apparatus or process concerned to the ground.

With the foregoing and other objects in view which will appear as the description proceeds, the invention resides in the combination and arrangement of parts and in the details of construction hereinafter described and claimed, it being understood that changes in the precise embodiment of the invention herein disclosed can be made within the scope of what is claimed without departing from the spirit of the invention.

The invention is illustrated in the accompanying drawing, wherein:

Figure 1 is a side elevation with parts broken away and parts in cross section illustrating the magnetic grounding electrode.

Figure 2 is a side view of a portion of the dry cleaning washer showing the grounding electrode installed therein, dotted lines indicating the magnetic field thereabout.

Figure 3 is a symbolic view of a pair of rolls in a rotary printing press illustratin the application of the magnetic grounding electrode thereto, dotted lines indicating the magnetic field therein.

By referring to the drawings and Figure 1 in particular it will be seen that a grounding electrode has been disclosed which comprises an elongated metal object, preferably tubular in shape, and i indicated by the numeral I0 and formed of a material forming a good electrical conductor. For this purpose, a copper tube provided with a silver coating has been found to be highly efiicient. One end of the electrode I0 is mechanically and electrically secured -to a threaded plug I I which in turn is provided with a plurality of annularly spaced, fiat facets I2 and a connection screw I3. The other end of the electrode is inwardly flanged and is provided with a section of a permanent magnet material I4 such a Alnico, a portion of which preferably extends beyond the electrode Ill. The permanent magnet material I4 is mounted in the end of the electrode I0 in a liquid-tight manner as by soldering the same therein. The magnet material I4 is magnetized so that the line of flow of magnetic current is from one end of the magnet material I4 to the other, as shown by the dotted lines in Figure 1 of the drawings and as characteristic of a permanent magnet. If desired, additional permanent magnet material I 4 may be positioned intermediate the ends of the electrode II) by securing the same in the electrode 10 in spaced relation to one another.

The grounding electrode in use is illustrated in Figure 2 of the drawings wherein a casing I5 of i a. dry cleaning washer is illustrated and wherein the rotatable basket I3 is positioned for the reception of garments to be cleaned. The rotatable basket I 6 is provided with a plurality of perforations I! as known in the art and an access door enclosure (not shown).

The grounding electrode I0 is illustrated in position in the area between the exterior of the basket I6 and the interior of the housing I5 with the threaded plug II being secured in a drilled and tapped opening in the housing I5 so that the connection screw I3 is on the exterior of the housing while the electrode I0 is on the interior thereof and spaced with respect to both the basket I 6 and the housing I5. An electrical conductor I8 is connected to the electrode by means of the connection screw l3 and run to a ground I9. Dotted lines in Figure 2 indicate the magnetic current flow lines from the section of permanent magnetic material I4 in the grounding electrode Ill. These dotted lines are generally indicated by the letter M.

It will thus be seen that static currents gen- 1 erated in the dry cleaning washer and within the housing I5 in the solvent normall used therein as upon the rotation of the basket [6 with garments therein will be in the area of the magnetic field M of the magnet material i l and that such static currents as are generated will be directed and/or deflected by the magnetic current lines of flow M to the magnet and the electrode l thereby enabling the electrode iii to form an effective ground path or collecting agency for the electro-static currents The elec-- trode I0 is formed of an excellent electrical conductor and when connected with a good ground through the electrical conductor [8 provides an efficient ground by reason of its relative lack of resistance as compared with the housing P of the washer itself or the mechanical apparatus in connection therewith. The grounding electrode therefore operates to continually drain away static currents as the same are generated to the end that the clothes in the washer do not build up static charges and do not therefore attract soil particles freed by the solvent. This freedom of electro-static attraction on the part of the garments eliminates graying as known in the dry cleaning industry and which is recognized as comprising a re-depositation of the soil removed from the garments by the solvent action of the washer.

Many and various other applications of the magnetic grounding electrode will occur to those skilled in the art and among such will be the application of the magnetic grounding electrode to rotary printing presses. Such an application is illustrated symbolically in Figure 3 of the drawings and by referring thereto it will be seen that a pair of opposed rolls are illustrated and indicated by the numerals 2e and 21. A grounding electrode 22 of the. modified nature is illustrated in proximity to the rolls 2i} and 21 and comprises a rod or a tube having a plurality of permanent magnets positioned at intervals therealong so that th magnetic fields from each of the magnets, as indicated by the letters M, lie in contact with or proximity to the rolls 28 and/ or any film or sheet material processed thereon. The grounding electrode is provided with a mounting bracket 24 and an electrical conductor 25 connects the electrode 22 with a good ground 26.

This particular application of the invention represents a solution of a problem for which various static grounding systems have been proposed, y

among them the use of grounding electrodes including radioactive material emitting alpha and beta radiation to form paths for the static currents generated by the apparatus. Such grounding electrodes have proved harmful to personnel and they are quite expensive in manufacture and maintenance.

In the preferred form of the invention, as illustrated in Figures 1 and 2 of the drawings, the tubular body of the electrode is formed of copper with a silver plating thereover, the silver plating forming a contaminating agent with respect to the solvent in the dry cleaning washer whereby extremely minute quantities of silver salts are released into the solventto facilitate the grounding action of the said electrode with respect to electrostatic currents generated in the washer.

The magnetic grounding electrode shown herein is also useful in application to calendering machines as used in the processing of various sheet and film-like materials including synthetic. rubbers and cellulose tissue products and the like.

It will thus be seen that a magnetized grounding electrode has been disclosed which meets the several objects of the invention.

42?. Having thus described my invention, what I claim is:

1. A magnetic grounding electrode comprising a hollow section of conducting material having at least one permanent magnet positioned partially therein and protruding partially therefrom, the poles of the magnet being spaced with respect to said conducting material, the magnetic field of which directs and deflects electrostatic currents to the said section of conducting material, and connection means for grounding the said section of conducting material to a suitable ground.

2. A grounding electrode comprising a tubular section of electrical conducting material having one end thereof inwardly flanged, a permanent magnet positioned in said inwardly flanged end thereof so that one pole of the magnet lies beyond the end of the tubular material and the other lies within the area of the end of the tubular material, and connecting means on the said grounding electrode establishing electrical connection with a ground.

3. The groundin electrode as set forth in claim 2 wherein the tubular material is coated with a secondary electrical conductor characterized by its ability to form an oxide or salt useful as a contaminating agent in a body of dry cleaning fluid.

4. A grounding electrode comprising a rod having a hollow end, a permanent magnet positioned in said end so that one pole of the magnet lies beyond the rod and the other pole lies within the hollow end of the rod, and connection means on the said grounding electrode establishing electrical connection with a ground.

5 A grounding electrode comprising a rod of non-conducting material having a permanent magnet positioned in one end thereof so that one pole of the magnet lies beyond the rod and the other pole lies within the area of the end of the rod, the said rod having a coating of an electrical conducting material thereover, and connection means on the said grounding electrode establishin electrical connection with a ground.

6. A grounding electrode comprising a tubular section of electrical conducting material having a permanent magnet positioned in one end thereof so that one pole of the magnet lies beyond the end of the tubular material and the other lies within the area of the end of the tubular material and spaced with respect thereto, and a threaded plug secured to the other end of the said grounding electrode and providing means for mounting the sam in a drilled and tapped opening, electrical connection means on the outermost end of the said plug to facilitate connection of the grounding electrode to a ground.

WEBSTER B. HARPMAN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS N mb a a 1,925,856 Vaughan Sept. 5, 1933 2,176,118 Linde Oct. 17, 1939 2,285,440 Kaiser June 9, 1942 2,449,972 Beach Sept. 28, 1948 OTHER REFERENCES Magnetism and Electricity, by v Brooks and Poyser, published by Long mans qreen andCo 1927, pages 243, 485 and 486. 

